We have developed a variety of tasks to activate regions of interest in functional neuroimaging studies. 1. To examine the distinction between recall and familiarity in episodic memory function we have developed a task using visual scenes that reliably induces familiarity based errors in controls. 2. We assessed the role of Catecol-O-methyltransferase(COMT) genotype in a functional Magnetic Resonance Imaging (fMRI) event related study which gauged the effects of cognitive control on various conditions involving interference in the so called flanker task. 3. We developed a carefully matched set of verbal fluency tasks to examine the relation between semantic processing, thought disorder, and neurophysiology in schizophrenia using PET CBF (Positron Emission Tomography Cerebral Blood Flow) methods. We found an area in inferior prefrontal cortex (PFC) that was more activated in semantic fluency and correlated with a classic symptom of schizophrenia -- thought disorder. 4. We are using a novel updating task which allows the amount of "updating" to be varied parametrically by demanding operations on single or multiple frames within each trial. This technique will allow us to examine whether there is an interaction between load and delay in the dorsolateral prefrontal cortex and how and whether such interactions may engage different subdivisions within the prefrontal cortex.